'Happy hormone' crucial in preventing diabetes
Diabetes is growing into one the biggest health problems in the world and is now responsible for nearly 4 million deaths a year. A team of researchers studied the role of the hormone serotonin, which is stored in the pancreas along with insulin, to see if its absence had any effect on insulin production. Their results showed that the absence of serotonin in the pancreas of mice led to their rapidly developing diabetes. The results, published in the journal Public Library of Science (PLoS) Biology, offer a promising new direction in diabetes research. Diabetes is the most widespread metabolic disease in the developed world and pioneering research is crucial in addressing this worldwide health emergency. Diabetes causes serious health problems including stroke, blindness and kidney failure. It is also causing a huge economic burden on health service resources worldwide. Now a breakthrough has occurred. An international consortium of scientists has identified the role that serotonin plays in the insulin-producing cells of the pancreas and consequently in the development of diabetes. The consortium, led by the Max Planck Institute for Molecular Genetics in Berlin, Germany, included researchers from the University of Maribor, Slovenia, and the Institute of Pharmacology and Toxicology at the Free University Berlin, Germany. The team carried out experiments on mice and found that the absence of serotonin is a precursor for the development of diabetes. Serotonin has long interested the scientific community. Called the 'feel-good hormone' because high serotonin levels make you feel happy, it affects many aspects of human behaviour such as mood, relaxation levels and the ability to sleep. Serotonin plays many roles in the body. It works as a neurotransmitter in the brain, and is found in blood platelets and in the intestinal walls. It is also present in the beta cells in the pancreas which release insulin to regulate blood glucose levels. Serotonin was discovered in beta cells more than 30 years ago, but the exact connection between it and the development of diabetes has not been not uncovered until now. Insulin and serotonin are both stored in beta cells in the pancreas. When insulin is released from the pancreas, it plays a crucial role in regulating blood glucose levels by distributing sugar in the bloodstream to other cells, effectively feeding blood sugar to cells throughout the body and then lowering blood sugar levels if they remain too high in the bloodstream. Diabetes occurs when this regulatory mechanism stops working properly. The research team carried out experiments on mice that lacked an enzyme called tryptophan hydroxylase, essential for production of serotonin in the body. Without this enzyme, the mice were unable to produce serotonin and developed signs of diabetes. They were also resistant to pargyline, a chemical that normally precipitates insulin release. The team found that when serotonin levels were low, insulin production in the mice was lowered and blood glucose levels rose swiftly after they ate. 'Under normal conditions, serotonin controls the release of insulin, the most important hormone in the regulation of blood glucose concentration of humans and animals,' explained Dr Diego Walther from the Max Planck Institute of Molecular Genetics. The research team hope their discovery will open the way for further research and offer hope for diabetes sufferers.
Countries
Germany, Slovenia
